Following advancement of digital technology for electronic equipment, there is great demand for a solid-state storage device of increased capacity and for accelerating data transfer so as to lessen the amount of time to store data. U.S. Pat. No. 6,204,139 discloses one such technique for meeting these demands. The technique includes forming a solid-state storage device using a perovskite material (e.g., Pr1-xCaxMnO3(PCMO), LaSrMnO3(LSMO), or GdBaCoxOy(GBCO)), which has a resistance which changes in accordance with an applied electric pulse. As such, perovskite material may be used to store different numeric values.
In addition, J. Appl. Phys., Vol. 84, (1998), p5647, proposes a memory element using a deep acceptor level and a shallow donor level of an amorphous carbon film in which the film's resistance changes according to injected charges.
Although these materials are said to have variable resistances, it is not disclosed specifically the structure and characteristics of these materials and other materials that may be best suited for a memory. As well, characteristics of these materials are destroyed in semiconductor processing.